Techniques for web service black box testing

ABSTRACT

A technique for synthesizing tests from a Web service document includes locating at least one parameter for at least one client to server function call in a Web service document. Client validation constraints for the at least one parameter are discovered. Server validation constraints for the at least one parameter in the Web service document are discovered. At least one range for the at least one parameter that will be accepted by the server and not be accepted by the client is discovered. Tests using parameter values from the discovered at least one range are synthesized.

This application is a national stage of International Application No.PCT/IB2014/058492, which was filed on Jan. 23, 2014, and claims priorityto United Kingdom Patent Application 1303562.1, entitled “WEB SERVICEBLACK BOX TESTING,” filed on Feb. 28, 2013. The disclosures ofInternational Application No. PCT/IB2014/058492 and United KingdomPatent Application 1303562.1 are hereby incorporated herein by referencein their entirety for all purposes.

BACKGROUND

This application is generally directed to Web service black box testingand, more particularly, to synthesizing effective payloads for black boxtesting of Web services.

Web services are a central component in the design of Web systems. A Webservice may provide remote online functionality to Web applications andother Web services. Automated black box testing of Web services forfunctional problems (for example, security vulnerabilities) is achallenge, even compared to black box testing of Web applications. A keyreason for this is that the return value of a Web method in a WebService is typically a primitive value like an integer or a Boolean(though in principle the Web method may return an arbitrary object).This is unlike a Web application iteration where the returned result ofan Internet hypertext transfer protocol (HTTP) request is an HTTPresponse that can be analyzed to determine whether the test payload wassuccessful.

A significant gap in expressiveness between an HTTP response and aprimitive value hinders the applicability of black box validationtechniques from testing of Web applications to Web services. In sum,there is simply not enough information in the result of a Web service tomake any educated or principled estimation about the success of anattack. A classic example of this, from the space of security testing,is checking for cross-site scripting (XSS) vulnerabilities, where Webapplication validation checks whether an input payload (a script) iscontained in a hypertext markup language (HTML) document returned by theWeb application. The same test cannot be performed if the returned valueis a number as is likely for a Web service.

The only way of getting sufficient feedback from a Web service, suchthat black box validation can be applied, is if the Web service isdriven into an error condition, in which case its return value isnormally an error message that often contains data from the inputpayload. The data published as part of the response can then besubjected to validation, for example, by looking for the input script inthe error message.

Naturally, however, the error message would be considered interestingonly if it is due to an illegal behavior within the business logic ofthe Web service. Otherwise, if the cause of the exception is asuperficial validation step in the outer layers of the Web service,where the scanner has not exercised the “true” functionality of the Webservice, testing is shallow and incomplete. For example, such anexception can occur during parsing of an incoming input message or whenchecking whether a number is within legal bounds.

BRIEF SUMMARY

Disclosed are a method, a data processing system, and a computer programproduct (embodied in a computer-readable storage device) for Web serviceblack box testing.

A technique for synthesizing tests from a Web service document includeslocating at least one parameter for at least one client to serverfunction call in a Web service document. Client validation constraintsfor the at least one parameter are discovered. Server validationconstraints for the at least one parameter in the Web service documentare discovered. At least one range for the at least one parameter thatwill be accepted by the server and not be accepted by the client isdiscovered. Tests using parameter values from the discovered at leastone range are synthesized.

The above as well as additional objectives, features, and advantages ofthe present invention will become apparent in the following detailedwritten description.

BRIEF DESCRIPTION OF THE DRAWINGS

The description of the illustrative embodiments is to be read inconjunction with the accompanying drawings, wherein:

FIG. 1 is a deployment diagram according to one embodiment of thepresent disclosure;

FIG. 2 is a component diagram according to one embodiment of the presentdisclosure;

FIG. 3 is a flow diagram of a process according to one embodiment of thepresent disclosure;

FIGS. 4, 5, 6 and 7 are code examples according to embodiments of thepresent disclosure; and

FIG. 8 is a component diagram according to another embodiment of thepresent disclosure.

DETAILED DESCRIPTION

The illustrative embodiments provide a method, data processing system,and a computer program product (embodied in a computer-readable storagedevice) for Web service black box testing.

In the following detailed description of exemplary embodiments of theinvention, specific exemplary embodiments in which the invention may bepracticed are described in sufficient detail to enable those skilled inthe art to practice the invention, and it is to be understood that otherembodiments may be utilized and that logical, architectural,programmatic, mechanical, electrical and other changes may be madewithout departing from the spirit or scope of the present invention. Thefollowing detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims and equivalents thereof.

It is understood that the use of specific component, device and/orparameter names are for example only and not meant to imply anylimitations on the invention. The invention may thus be implemented withdifferent nomenclature/terminology utilized to describe thecomponents/devices/parameters herein, without limitation. Each termutilized herein is to be given its broadest interpretation given thecontext in which that term is utilized. As may be utilized herein, theterm ‘coupled’ encompasses a direct electrical connection betweencomponents or devices and an indirect electrical connection betweencomponents or devices achieved using one or more intervening componentsor devices.

According to one embodiment, a method of synthesizing tests from a Webservice document comprises: locating at least one parameter for at leastone client-server function call in a Web service document; discoveringclient validation constraints for the at least one parameter;discovering server validation constraints for the at least oneparameter; and discovering a range for the at least one parameter thatwill be accepted by the server and not be accepted by the client.

According to one embodiment of the present disclosure, a method forsynthesizing inputs for black box testing of Web services ensures thatan input payload reaches Web service business logic and a Web service isdriven into an illegal state, thereby returning an error message that isamenable to black box validation. An assumption in the disclosedembodiments is that client side code that uses a Web service isavailable for inspection. What makes this assumption natural is thatoften a Web service is tested as part of a Web application consuming itsservices. In at least one embodiment, client code is part of a Webservice (before it is sent to a client), but in other embodiments clientcode may not be physically part of a Web service.

Given the above assumption, the disclosed techniques simultaneouslyconsider constraints enforced by a client and constraints enforced by aWeb service, such that a range of data values “falling in the gap”between client side and server side validation can be obtained. Thesevalues are interesting since: being compatible with server sideconstraints they pass through an outer layer of the Web service and intobusiness logic; and being incompatible with client side constraints theyare often illegal in practice, thereby resulting in an error condition.

To appreciate this observation, the reasons for discrepancies betweenclient side and server side validation in Web services are explainedand, in particular, the reason why server side validation is often lessthan approximate (that is, admits values that trigger an error state).First, constraints on Web methods are often generated automaticallybased on the parameters types in a Web service Web service definitionlanguage (WSDL) document and/or its associated schema. For example, if aparameter for human objects is of type “age”, then the parameter valuewill likely be in the range 0-120 years from the server perspective,whereas the client application may expect a more limited range of 6-18years denoting the age of a school student. The client application mayenforce such a restricted range. Second, the constraints are typicallycreated once per Web service (for all methods in the WSDL file) or evenfor multiple Web services using shared libraries, and so need to becompatible for all parameters in all Web methods.

A test comprises a Web request involving a parameter having a value orrange. For instance, one might request all people having an age between18 and 21 years. In one embodiment a Web service comprises Web methodsthat are the server side of the Web service and are located in a Webservice document or a WSDL document. In one or more embodiments, allmethod calls in client side code of a Web service document are analyzedfor constrained parameters. In various embodiments, tests are builtusing parameter values from a discovered range. In one or moreembodiments, the tests are executed and any errors generated arerecorded. In an embodiment, known modifications to the generated errorsare searched for and the Web service is changed in accordance with themodifications. Embodiments can lead to a physical correction of a Webservice carried on outside a computer when an error is detected.Embodiments operate below the level of the Web service at the machinelevel of a computer so that a Web Service has no knowledge that it isunder test.

According to another aspect a system for synthesizing tests from a Webservice document includes: a function call identifier for locating atleast one parameter for at least one client to server function call in aWeb service document; a client constraint discovery engine fordiscovering client validation constraints for the at least oneparameter; a server constraint discovery engine for discovering servervalidation constraints for the at least one parameter; a rangeidentifier for discovering a range for the at least one parameter thatwill be accepted by the server and not be accepted by the client; and atest synthesizer for building tests using values in the identifiedrange.

According to another aspect, a computer program product for formulatingtests from a Web service document, includes: a computer-readable storagemedium having computer-readable program code embodied thereon. Thecomputer-readable program code, when executed by a data processingsystem, is configured to perform the processes described herein. In atleast one embodiment, the computer program product comprises a series ofcomputer-readable instructions fixed on a tangible medium, such as anoptical disk, a magnetic disk, or a solid-state drive. The series ofcomputer readable instructions embodies all or part of the functionalitypreviously described herein. Those skilled in the art will appreciatethat such computer readable instructions can be written in a number ofprogramming languages for use with many computer architectures oroperating systems. Further, such instructions may be stored using anymemory technology, present or future, including but not limited to,semiconductor, magnetic, or optical. It is contemplated that such acomputer program product may be distributed as a removable medium withaccompanying printed or electronic documentation, for example,shrink-wrapped software, pre-loaded with a computer system, for example,on a system ROM or fixed disk, or distributed from a server orelectronic bulletin board over a network, for example, the Internet orWorld Wide Web.

According to another aspect, a computer program stored on a computerreadable medium and loadable into the internal memory of a digitalcomputer, comprising software code portions, when the program is run ona computer, performs the processes described herein. In anotherembodiment, a data carrier comprises functional computer data structureswhich, when loaded into a computer system (data processing system) andoperated upon thereby, cause the computer system to perform thedisclosed processes. A suitable data-carrier could be a solid-statememory, a magnetic drive, or an optical disk.

Referring to FIG. 1, the deployment of an embodiment in a computerprocessing system 10 is described. Computer processing system 10 isoperational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing processing systems, environments, and/or configurations thatmay be suitable for use with computer processing system 10 include, butare not limited to, personal computer systems, server computer systems,thin clients, thick clients, hand-held or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices.

Computer processing system 10 may be described in the general context ofcomputer system-executable instructions, such as program modules, beingexecuted by a processor. Generally, program modules may includeroutines, programs, objects, components, logic, and data structures thatperform particular tasks or implement particular abstract data types.Computer processing system 10 may be embodied in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As is illustrated, computer processing system 10 includes:general-purpose computer server 12 and one or more input devices 14 andoutput devices 16 directly attached to the computer server 12. Computerprocessing system 10 is connected to a network 20. Computer processingsystem 10 communicates with a user 18 using input devices 14 and outputdevices 16. Input devices 14 include one or more of: a keyboard, ascanner, a mouse, trackball or another pointing device. Output devices16 include one or more of a display or a printer. Computer processingsystem 10 communicates with network devices (not shown) over network 20.Network 20 can be a local area network (LAN), a wide area network (WAN),or the Internet.

Computer server 12 comprises: a central processing unit (CPU) 22;network adapter 24; device adapter 26; bus 28 and memory 30. CPU 22loads machine instructions from memory 30 and performs machineoperations in response to the instructions. Such machine operationsinclude: increment or decrement a value in register (not shown);transfer a value from memory 30 to a register or vice versa; takeinstructions from a different location in memory if a condition is trueor false (also known as a conditional branch instruction); and add orsubtract the values in two different registers and put the result inanother register. A typical CPU can perform many different machineoperations. A set of machine instructions is called a machine codeprogram. Machine instructions are written in a machine code languagewhich is referred to a low level language. A computer program written ina high level language needs to be compiled to a machine code programbefore it can be run. Alternatively a machine code program such as avirtual machine or an interpreter can interpret a high level language interms of machine operations.

Network adapter 24 is connected to bus 28 and network 20 forfacilitating communication between the computer server 12 and networkdevices. Device adapter 26 is connected to bus 28 and input devices 14and output devices 16 for facilitating communication between computerserver 12 and input devices 14 and output devices 16. Bus 28 couples themain system components together including memory 30 to CPU 22. Bus 28represents one or more of any of several types of bus structures,including a memory bus or memory controller, a peripheral bus, anaccelerated graphics port, and a processor or local bus using any of avariety of bus architectures. By way of example, and not limitation,such architectures include Industry Standard Architecture (ISA) bus,Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, VideoElectronics Standards Association (VESA) local bus, and PeripheralComponent Interconnects (PCI) bus.

Memory 30 includes computer system readable media in the form ofvolatile memory 32 and non-volatile or persistent memory 34. Examples ofvolatile memory 32 are random access memory (RAM) 36 and cache memory38. Generally volatile memory is used because it is faster and generallynon-volatile memory is used because it will hold the data for longer.Computer processing system 10 may further include other removable and/ornon-removable, volatile and/or non-volatile computer system storagemedia. By way of example only, persistent memory 34 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically a magnetic hard disk or solid-state drive).Although not shown, further storage media may be provided including: anexternal port for removable, non-volatile solid-state memory; and anoptical disk drive for reading from or writing to a removable,non-volatile optical disk such as a compact disk (CD), digital videodisk (DVD), or Blu-ray. In such instances, each can be connected to bus28 by one or more data media interfaces.

As will be further depicted and described below, memory 30 may includeat least one program product having a set (for example, at least one) ofprogram modules that are configured to carry out the functions of thedisclosed embodiments. The set of program modules configured to carryout the functions of the various embodiments comprises: a Web server100; a Web service 102; tests 104; a test engine 106, and a test module200. Additional program modules that support the various embodiments arenot shown, but include firmware, a boot strap program, an operatingsystem, and support applications. Each of the operating system, supportapplications, other program modules, and program data or somecombination thereof, may include an implementation of a networkingenvironment.

Computer processing system 10 communicates with at least one network 20(such as a local area network (LAN), a general wide area network (WAN),and/or a public network like the Internet) via network adapter 24.Network adapter 24 communicates with the other components of computerserver 12 via bus 28. It should be understood that although not shown,other hardware and/or software components may be used in conjunctionwith computer processing system 10. Examples, include, but are notlimited to: microcode, device drivers, redundant processing units,external disk drive arrays, redundant array of independent disks (RAID),tape drives, and data archival storage systems. Web server 100 enablescomputer server 12 to execute Web services such as Web service 102 inorder to provide services to computer clients 8. A computer client issimilar to computer server 12 and connected via network 20 to computerserver 12.

Web service 102 is a document comprising instructions to instruct Webserver 100 how to operate in order to provide a defined service to aclient. Web service 102 comprises Web methods 107 and client code 108.Web methods 107 are server side methods that deal with requests fromclient code 108. Client code 108 is client side application code that issent to a requesting client after an initial request from a client forWeb service 102. During normal operation client code 108 is executed ona computer client that is a different physical device to the computerserver. When executing on a computer client, client code 108communicates with Web methods 107 on the computer server to perform thedefined service. Tests 104 are, at their simplest, Web requestssynthesized by test module 200 and executed by a test engine 106 inorder to initiate and control communication with a Web service. Oftenthe tests simulate a client executing client code 108. Test engine 106executes tests 104 in order to simulate a client using the Web service.Test module 200 synthesizes tests 104 for use by test engine 106.

Referring to FIG. 2, test module 200 comprises: function call identifier202; client constraint discovery engine 204; server constraint discoveryengine 206; range identifier 208; test synthesizer 210; and test method300. Function call identifier 202 is configured to scan a Web servicedocument for identify function calls between client and server code withcorresponding parameters. Client constraint discovery engine 204 isconfigured to discover client code validation constraints within theclient side code of Web service document for the correspondingparameters. Server constraint discovery engine 206 is configured todiscover server code validation constraints within the server side codeof the Web service document. Range identifier 208 is configured tocalculate the range or ranges of parameter values, for each identifiedcorresponding parameter, that are satisfied by the server constraintsand not satisfied by the client constraints. Test synthesizer 210 isconfigured to build tests from the identified range or ranges ofparameter values.

Test method 300 is configured to control the components of test module200 using a series of logical processes described below. Referring toFIG. 3, test method 300 comprises logical process blocks 301 to 305;inputs 306; and output 307. Inputs 306 comprise Web service 102; Webmethods 107; and client code 108. Output 307 comprises the differencebetween the server side and client side constraints. Block 301 isconfigured to analyze each function call in client code 108 to find,using static analysis, parameters and validation steps that areperformed as part of the call. One way of doing this is by identifyingvalidation functions within the client code (typically HTML validationfunctions) and checking for data dependencies between the validators andthe parameters used. Client side validators often use standard frameworkbased micro-validators and/or regular-expression matching on userinputs, and can thus be detected by simple comparison.

Block 302 is configured to locate one or more validators that governeach client function call and subsequently to discover clientconstraints on the parameters in the function call by applying staticanalysis to the one or more validators. For regular expressionsconstraining parameters of a string type, regular expressions describingall legal inputs are derived. For interval checks or other boundsconstraining numeric parameters, parameter ranges are derived usinginterval analysis. Parameters that violate client side validation areexpected to cause errors both at the level of server side extendedmarkup (XML) schema validation and within the business logic of the Webservice.

Block 303 is configured to discover server side constraints forparameter values in Web methods 107. These are defined in Web service102, and may also appear in a policy file associated with a Web service.Parameters violating the server side constraints will not reach thebusiness logic, causing an error during XML validation during processingof an incoming message. Block 304 is configured to compute a pass rangeas the difference between the client side and server side constraints oninput parameters. The pass through range is a range of inputs that willarrive at the business logic and lead to execution at the client level.Block 305 is configured to synthesize one or more tests using testvalues in the pass range.

Referring to FIGS. 4, 5, 6, and 7, exemplary operations are describedwith respect to code examples. Line numbers in the code examples are forreference purposes only and do not form part of the code. Referring toFIG. 4, client application 108 is illustrated as a hypertext markuplanguage (HTML) form that is sent to a client as part of a servicerequest.

-   -   4.1 defines an HTML form called “EnrollInSchoolForm”;    -   4.2 defines a label for parameter “name”;    -   4.3 defines a label for parameter “age”;    -   4.4 defines text as the input type for the parameter “name”;    -   4.5 defines text as the input type for the parameter “age”;    -   4.6 defines a button as an input having a submit id;    -   4.7 is the end of the form definition.

Referring to FIG. 5, exemplary client validation code that is part ofclient application 108 is illustrated.

-   -   5.1 defines a function associated with the Web service;    -   5.2 defines a function associated with the submit button defined        in the HTML code;    -   5.3 defines a validator for the “EnrollInSchoolForm”;    -   5.4 said validator having the following rules;    -   5.5 whereby the age must be in the range 6 to 17;    -   5.6 end of validator;    -   5.7 if not valid then send an error message “errName”;    -   5.8 end;    -   5.9 end;    -   5.10 end.

Referring to FIG. 6, exemplary asynchronous script code (in this caseAsynchronous JavaScript (AJAX)) that is part of client code 108 forcalling Web methods 107 is illustrated.

-   -   6.1 defines a function associated with the Web service;    -   6.2 defines a function associated with the submit button defined        in the HTML code, as opposed to the previous client side        validation, this function will call a server side validation        method;    -   6.3 defines a name for the function;    -   6.4 defines the parameters to be sent to the Web server;    -   6.5 serialized the parameters to be sent to the Web server;    -   6.6 prepares to send a message;    -   6.7 prepares message characteristics;    -   6.8 defines send type;    -   6.9 defines the universal resource location;    -   6.10 defines the contents of a message;    -   6.11 defines message content type;    -   6.12 defines message data type;    -   6.13 defines success conditions;    -   6.14 defines error conditions;    -   6.15 end;    -   6.16 end;    -   6.17 end.

Referring to FIG. 7, an exemplary server side schema extended mark uplanguage schema (XSD) taken from Web service 106 is illustrated.

-   -   7.1 defines a schema for the element “age”;    -   7.2 defines that the schema is a simple type;    -   7.3 defines that the element is an integer;    -   7.4 defines the minimum value as inclusive of zero;    -   7.5 defines the maximum value as inclusive of 120;    -   7.6 end;    -   7.7 end;    -   7.8 end.

The code includes an AJAX call (line 6.9) to Web methodMunicipalService.asmx/EnrollInSchoolForm which uses the input values ofparameters name and age. The age parameter is also accessed from thevalidation code of FIG. 5 which uses standard micro-validators. Datadependencies exist because both functions access the same inputvariables and, as such, the validation function is relevant to constrainthe values of parameter age used in calls toMunicipalService.asmx/EnrollInSchoolForm. The client range checks areanalyzed statically, and corresponding constraints are derived on thevalue of parameter age. In code line 5.5 of FIG. 5, parameter age isbound to range [6 to 17]. The parameter name is not constrained. Serverside constraints, found in code line 7.4 and 7.5 of FIG. 7, areretrieved. In the example, the Web service defines type Age, whosecorresponding range of values is 0 to 120. The intersection between theclient side constraints and server side constraints is computed. Theresulting ranges are [0 to 6] and [17 to 120]. If the parameter agecontains values from one of these ranges, then it will pass the serverside validation and reach the business logic, where it will cause anerror since the value is outside the [6 to 17] range.

Referring to FIG. 8, a further embodiment of the invention comprises astandalone debugging system 800 that integrates test module 200′, Webservice 102′; tests 104′; test engine 106′ with debugging engine 802 anderror correction engine 804. In this embodiment, the components labeledas primes are similar to unprimed components in the embodiment ofFIG. 1. In the embodiment of FIG. 8, test module 200′ is operationalduring real-time code development rather than at runtime. Debuggingengine 802 is configured to send messages to a developer when errors arefound in the Web service under development. Error correction engine 804is configured to match any error with a suggested fix and have debuggingengine 802 send it to the developer.

It should be clear to one of ordinary skill in the art that all or partof the logical process blocks may be alternatively embodied in a logicapparatus, or a plurality of logic apparatus, comprising logic elementsarranged to perform the logical blocks and that such logic elements maycomprise hardware components, firmware components, or a combinationthereof. It should be equally clear to one of skill in the art that allor part of the logic components may be alternatively embodied in logicapparatus comprising logic elements to perform the disclosed blocks, andthat such logic elements may comprise components such as logic gates in,for example a programmable logic array or application-specificintegrated circuit. Such a logic arrangement may further be embodied inenabling elements for temporarily or permanently establishing logicstructures in such an array or circuit using, for example, a virtualhardware descriptor language, which may be stored and transmitted usingfixed or transmittable carrier media.

In a further alternative embodiment, a computer implemented method ofdeploying a service comprises deploying computer program code operableto, when deployed into a computer infrastructure and executed thereon,cause a computer system to perform the disclosed blocks. It should beappreciated that the disclosed processes and components mayalternatively be embodied fully or partially in a parallel computingsystem comprising two or more processors for executing parallelsoftware. It should be clear to one skilled in the art that manyimprovements and modifications can be made to the foregoing exemplaryembodiments without departing from the scope of the present invention.

Accordingly, techniques have been disclosed herein that advantageouslyfacilitate Web service black box testing.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular system,device or component thereof to the teachings of the invention withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the invention not be limited to the particular embodimentsdisclosed for carrying out this invention, but that the invention willinclude all embodiments falling within the scope of the appended claims.Moreover, the use of the terms first, second, etc. do not denote anyorder or importance, but rather the terms first, second, etc. are usedto distinguish one element from another.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below, if any, areintended to include any structure, material, or act for performing thefunction in combination with other claimed elements as specificallyclaimed. The description of the present invention has been presented forpurposes of illustration and description, but is not intended to beexhaustive or limited to the invention in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the invention.The embodiments were chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. A method of synthesizing tests from a Web servicedocument, comprising: locating, using a data processing system, at leastone parameter for at least one client to server function call in a Webservice document; discovering, using the data processing system, clientvalidation constraints for the at least one parameter; discovering,using the data processing system, server validation constraints for theat least one parameter; discovering, using the data processing system,at least one range for the at least one parameter that will be acceptedby the server and not be accepted by the client; and synthesizing, usingthe data processing system, one or more tests using parameter valuesfrom the at least one range, wherein the values in the at least onerange pass server side validation and reach Web services business logicwhich causes an error to be generated in response to execution of thetests, and wherein a function call identifier analyzes calls in clientside code of the Web service document for constrained parameters and thevalues in the at least one range fall within a gap between client sidevalidation range and server side validation range.
 2. The method ofclaim 1, further comprising: executing the tests and recording anyerrors generated.
 3. The method of claim 2, further comprising:identifying a best modification from known modifications for a generatederror and changing the Web service document in accordance with the bestmodification.
 4. The method of claim 1, wherein an error is detectedduring realtime Web service development.
 5. The method of claim 4,wherein an error correction for the detected error is suggested.
 6. Themethod of claim 5, wherein the suggested error correction is applied tothe Web service document.
 7. A computer system configured to synthesizetests from a Web service document, comprising: a memory; and one or moreprocessors coupled to the memory, wherein the processors are configuredto implement: a function call identifier configured to locate at leastone parameter for at least one client to server function call in a Webservice document; a client constraint discovery engine configured todiscover client validation constraints for the at least one parameter; aserver constraint discovery engine configured to discover servervalidation constraints for the at least one parameter; a rangeidentifier configured to discover at least one range for the at leastone parameter that will be accepted by the server and not be accepted bythe client; and a test synthesizer configured to build one or more testsusing values in the at least one range, wherein the values in the atleast one range pass server side validation and reach Web servicesbusiness logic which cause an error to be generated in response toexecution of the tests, and wherein the function call identifieranalyzes calls in client side code of the Web service document forconstrained parameters and the values in the at least one range fallwithin a gap between client side validation range and server sidevalidation range.
 8. The system of claim 7, wherein the processors arefurther configured to implement: a test engine configured to execute thetests and record any errors generated.
 9. The system of claim 8, whereinthe processors are further configured to implement: an error correctionengine configured to search for one or more known modifications to agenerated error and change the Web service document in accordance withthe modifications.
 10. The system of claim 7, wherein an error isdetected during realtime Web service development.
 11. The system ofclaim 10, wherein an error correction for the detected error issuggested.
 12. The system of claim 11, wherein the suggested errorcorrection is applied to the Web service document.
 13. A computerprogram product for synthesizing tests from a Web service document, thecomputer program product comprising: a computer-readable storage device;and computer-readable program code embodied on the computer-readablestorage device, wherein the computer-readable program code, whenexecuted by a data processing system, configures the data processingsystem to: locate at least one parameter for at least one client toserver function call in a Web service document; discover clientvalidation constraints for the at least one parameter; discover servervalidation constraints for the at least one parameter in the Web servicedocument; discover at least one range for the at least one parameterthat will be accepted by the server and not accepted by the client; andsynthesize one or more tests using parameter values from the at leastone range, wherein the values in the at least one range pass server sidevalidation and reach Web services business logic which causes an errorto be generated in response to execution of the tests, and wherein afunction call identifier analyzes calls in client side code of the Webservice document for constrained parameters and the values in the atleast one range fall within a gap between client side validation rangeand server side validation range.
 14. The computer program product ofclaim 13, wherein the computer-readable program code, when executed bythe data processing system, further configures the data processingsystem to: execute the tests and record any errors generated.
 15. Thecomputer program product of claim 14, wherein the computer-readableprogram code, when executed by the data processing system, furtherconfigures the data processing system to: identify a best modificationfrom known modifications for a generated error and change the Webservice document in accordance with the best modification.
 16. Thecomputer program product of claim 13, wherein an error is detectedduring real-time Web service development.
 17. The computer programproduct of claim 16, wherein an error correction for the detected erroris suggested, and wherein the suggested error correction is applied tothe Web service document.